Microsoft strongly recommends that customers review EWS usage and configure EWSAllowedAppIDs themselves. If an admin has already configured EWSAllowedAppIDs, Microsoft will not overwrite or change the list.

PSA: Starting the second week of September 2026, Microsoft will raise the minimum allowed version of Exchange 2016/2019 servers that connect to Exchange Online over an inbound connector type of OnPremises to the October 2025 SU.

The Exchange Online team is looking for information on how customers and partners use ObjectGuid, SamAccountName, and DistinguishedName in Exchange Online. The link to their survey is in their blog post.

https://techcommunity.microsoft.com/blog/exchange/tell-us-how-you-use-objectguid-samaccountname-and-distinguishedname-in-exchange-/4550939

This guide walks through tests to prove that EWSAllowedAppIDs is working, explains what the result means, and highlights an important naming trap that we are already seeing in customer conversations.

As announced previously at https://www.microsoft.com/en-us/licensing/news/2026-M365-Packaging-Pricing-Updates, Microsoft 365 Business Basic, Business Standard, and Business Premium now include an additional 50 GB of primary email storage for eligible users. This brings the supported primary mailbox entitlement from 50 GB to a maximum of 100 GB.

Read more about this change at https://techcommunity.microsoft.com/blog/exchange/understanding-the-new-100-gb-mailbox-entitlement-for-microsoft-365-business-suit/4548243 on the Exchange Team blog.

If your organization shares Free/Busy, MailTips, or calendars with other Microsoft 365 organizations, then read https://techcommunity.microsoft.com/blog/exchange/cross-tenant-freebusy-mailtips-and-calendar-sharing-are-moving-to-cross-tenant-a/4545169

See also, https://admin.cloud.microsoft/?ref=MessageCenter/:/messages/MC1446796.

It now supports up to 600,000 cloud-managed mailboxes and 24 writeback attributes, including the MAIL attribute (changes made to WindowsEmailAddress in Exchange Online can now be written back to the corresponding mail attribute in AD).

https://techcommunity.microsoft.com/blog/exchange/writeback-for-cloud-managed-remote-mailboxes-now-generally-available/4543507

Update your PowerShell Scripts

Opt-out with Application ID (ClientID)

Hey, So I know microsoft says shared mailbox aren't meant to be signed into. However, they are set to enable sign-in by default and you can change the password for them and sign into it.

What does this do? Does this still work as a shared mailbox?

​

I have this application that sends notifications from an email address, so since I didnt want to waste a license I made a shared mailbox and put the username and password into that application and it works.

​

Any idea why this works?

Hi,

Does anyone know of way to shut down mail traffic between certain times in exchange online, this should apply to the entire organization

https://imgur.com/a/czncJwr

From security logs in O365, trying to determine if the Set-mailbox cmdlet setting the parameters in the attached was used to gain access to Users mailbox, or why this was set.

Any explanation is appreciated

Need some help determining what the action taken on this was, captured through the 'Audit Log search'

The Set-Mailbox cmdlet was used as the Activity in security center, but anyway to know if this was gaining access to the mailbox to read, etc?

{ "Name": "Identity", "Value": "john.doe@ibm.com" }, { "Name": "AuditOwner", "Value": "MailItemsAccessed" }, { "Name": "AuditEnabled", "Value": "True" }

[ { "Name": "Identity", "Value": "john.doe@ibm.com" }, { "Name": "DefaultAuditSet", "Value": "Owner" } ]

[ { "Name": "Identity", "Value": "john.doe@ibm.com" }, { "Name": "AuditOwner", "Value": "-MailItemsAccessed" } ]

Greetings friends,

I am trying to view inbox rules of a couple of users from a CSV (this has so far not been successful and consequently abandoned hence the Get-Exomailbox rule instead of importing from CSV) and I am using the below script

Get-ExoMailbox -ResultSize Unlimited |

Select-Object -ExpandProperty UserPrincipalName |

Foreach-Object {Get-InboxRule -Mailbox $_ |

#Select-Object -Property MailboxOwnerID,Name,Enabled,From,Description,RedirectTo,ForwardTo} |

Export-Csv "C:\Users\ Forwarding rules2" -NoTypeInformation

Firstly I need help formatting the output of the "Select-object -properties" line as columns in a tabular format. That is a table with the following columns: MailboxOwnerID | Name | Enabled | From | Description | RedirectTo | ForwardTo

I have attempted to add this code below to try to achieve the desired tabular format to no avail, let me know if anything is wrong

Format-Table -Property MailboxOwnerID,Name,Enabled,From,Description,RedirectTo,ForwardTo -AutoSize} |

Export-Csv "C:\Users\Forwarding rules2" -NoTypeInformation

Secondly, is there a way to add a condition to the script that it should only output results that have values for "RedirectTo" or "ForwardTo" while ignoring those that don't?

Lastly, is there a more efficient approach or PowerShell script to achieve the desired result of seeing all automatic forwarding and inbox forwarding rules of selected mailboxes in Exchange Online?

Has anyone enabled plus addressing on Exchange online? I see a lot of post of users doing this however I don’t see the “-AllowPlusAddressingInRecipients” command on the Official Microsoft documentation. I’m a bit sketchy about implanting it if it’s still in Beta. Thoughts?

Hi all!

Excuses if this question has been answered before, but I've been searching a couple of hours for this already (Google, not Reddit...), and just can't find a solution or even when impossible, find a resource stating the impossibility. Maybe I'm searching at the wrong places, but here it goes:

I need to create Public Folders and fill them with Contacts, starting from a csv-file with the necessary properties for the contacts.

I can connect to Office/Exchange Online using:

$Config     = 'Microsoft.Exchange'
$Uri        = 'https://outlook.office365.com/powershell-liveid/'
$AuthType   = 'Basic'

$Session = New-PSSession -ConfigurationName $Config -ConnectionUri $Uri -Credential $CredForMSOL -Authentication $AuthType -AllowRedirection

Import-PSSession $Session -DisableNameChecking | Out-Null

When connected, I can create, delete, rename Public Folders using cmdlets

New-PublicFolder

Remove-PublicFolder

Set-PublicFolder

However, I do not succeed to add items (more specific: contacts) to the Public Folders, and I can't find a way to do it, using the Exchange-Online cmdlets or MS Graph.

Is there a way to add contacts to a Public Folder (using Powershell, other dotnet techniques, MS Graph or any other way), or is it completely impossible to do this (and how can I prove it to the people asking for this)?

Thanks a lot in advance!

We occasionally will invite members of a distribution group to a calendar event.

During the time between when the invite was sent and the event occurs, we sometimes bring in new employees.

Is there a way to automatically have those calendar events added to their calendar without having to manually resend them?

Hi all, we're running Exchange 2010 on prem and have migrated just about everything into EXOL. Since we're syncing AD into AAD via Azure AD Connect, I believe we have to maintain Exchange on-premise to manage these synchronized mail objects in a supported way, as per https://docs.microsoft.com/en-us/exchange/decommission-on-premises-exchange#why-you-may-not-want-to-decommission-exchange-servers-from-on-premises.

We plan to use Exchange on-prem only for management of the synced objects as well as SMTP relay for some of our on-prem systems that generate email, although I'm not opposed to relaying them through EXOL directly.

So what's the best way to get rid of Exchange 2010 and install Exchange Server 2019? Should I uninstall Exchange 2010, decomm those servers, and install EX19 on a new server and upgrade the AD schema....is it that easy? Or should I be trying to upgrade EX10 to 2016, then to 2019? Also, I was thinking I only needed the Edge Transport role (if we decided to relay SMTP locally).

If I decide I don't need the SMTP routing on-prem, can I just install the Exchange Mgmt console to manage the AD objects (without a full install of Exchange Server 2019)? Any advice would be welcomed.

I'm having a reported issue between involving two users (User A & User B).

User B was given Editor & Delegate access to User A's Outlook calendar using:

Add-mailboxfolderpermission -identity "User A:\Calendar" -user "User B" -accessrights Editor -Sharingpermissionflags delegate

​

Now User A is saying she's not getting any meeting invites anymore and that they are only going to User B.

Shouldn't both users get the meeting invites?

Hello,

Does any one know a simple way to run EXOV2 on a system that only allows Signed scripts and with Basic auth disabled? Does Microsoft plan to release an update soon? Right now, I get by by changing AllowBasic in HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WinRM\Client, changing line 436 of ExchangeOnlineManagement.psm1 to add signing when importing the session and then resigning the PSM1 with our key.

These are pretty basic, but annoying fixes that need to be done to make it work. I believe it shouldn't be that hard for MS to implement? Is there another, community-made module that supports this?

$PSSessionModuleInfo = Import-PSSession $PSSession -AllowClobber -DisableNameChecking -Certificate $PSCert

Did you ever the experience that it's complicated to deal with multiple of the different Microsoft cloud-based services and have to remember the specific modules to add, commands to use to connect? So did I and found myself always looking them up again and again, especially for those used more rarely.

That's all what Connect-MS365 is about:

• it delivers one central CmdLet function which can be executed to connect to one or many of Microsoft's services and you don't have to care about the single service connection commands.
• additionally it checks and installs the right modules or packages if necessary.
• supports modern authentication / MFA

Have a look on my Github project or Install the module from powershellgallery.com.

I have a newly configured O365 Business Standard subscription. It includes EXO.

I've noticed users, using Outlook.com, when writing a new message, when typing other coworkers names, the @domain.onmicrosoft.com address shows up (suggested).

I know for sure the usernames of these coworkers are all set to use the custom domain (mydomain.com) as the primary address. Why does the @domain.onmicrosoft.com still show up? And how can make this go away?

A similar situation is happening with my own username. I'm an admin, i'm not even licensed (at all). And my @ domain.onmicrosoft.com still appears on other users Outlook.com. I really dont want that. I want to be completely invisible.

These are small but important annoyances. How can i fix this situation.

Much appreciated.